[Nek5000-users] Restarting with PNPN using PNPN-2 results
nek5000-users at lists.mcs.anl.gov
nek5000-users at lists.mcs.anl.gov
Wed Jun 15 22:22:52 CDT 2016
Philipp,
I am investigating a switch for two reasons:
1) to see how it affects my results. This is why I want to converge
pressure right away before performing more timesteps. I will be running
several more simulations that are similar to this one, and I am interested
in how PNPN will perform for the same flow. I have already put in a
significant amount of compute time into my current case and so I don't want
to start it over to perform this simple investigation.
2) I have an additional interest in post processing and analyzing the
pressure fluctuation field. Using PNPN over PNPN-2 makes sense in this case
since the pressure field is better resolved and enforces C0 continuity
across element boundaries.
Thanks,
Phil
On Wed, Jun 15, 2016 at 11:00 AM, <nek5000-users-request at lists.mcs.anl.gov>
wrote:
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> 1. Re: Restarting with PNPN using PNPN-2 results
> (nek5000-users at lists.mcs.anl.gov)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 15 Jun 2016 10:44:04 +0200
> From: nek5000-users at lists.mcs.anl.gov
> To: nek5000-users at lists.mcs.anl.gov
> Subject: Re: [Nek5000-users] Restarting with PNPN using PNPN-2 results
> Message-ID:
> <mailman.23825.1465980259.24727.nek5000-users at lists.mcs.anl.gov>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> Hi,
> I guess the question is whether there is a similar type of Uzawa
> iteration also for Pnpn, this I don't know and I have not looked into
> the theory. I can only say that for PnPn-2, with the nested iterations
> you can get a perfect pressure (i.e. not proportional to Delta p) in one
> time step. I guess one needs a PnPn user to answer that question.
>
> Just as a side question; why do you want to go from PnPn-2 to PnPn? Out
> of curiosity...
>
> Best regards,
> PHilipp
>
> On 2016-06-15 00:44, nek5000-users at lists.mcs.anl.gov wrote:
> > Philipp and Aleks,
> >
> > Thanks for the replies. The Uzawa method sounds exactly like what I am
> > looking for. I would like to pay a penalty upfront to converge to a
> > good pressure solution without taking too many (or really any) timesteps
> > and then move forward with a resolved pressure solution. I am hoping
> > there is a way to do this since a pressure projection method is being
> used.
> >
> > My solution is already well resolved temporally and I don't want to
> > perturbe it with a long time series of unresolved pressure
> > fields/slightly divergent velocity fields. Can anyone comment on the use
> > of Uzawa with PNPN? Also, Philipp is there a specific routine you call
> > to perform just one of these iterations? I haven't used this method
> before.
> >
> > Kind regards,
> >
> > Phil
> >
> > On Tue, Jun 14, 2016 at 11:00 AM,
> > <nek5000-users-request at lists.mcs.anl.gov
> > <mailto:nek5000-users-request at lists.mcs.anl.gov>> wrote:
> >
> > Send Nek5000-users mailing list submissions to
> > nek5000-users at lists.mcs.anl.gov
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> >
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> > or, via email, send a message with subject or body 'help' to
> > nek5000-users-request at lists.mcs.anl.gov
> > <mailto:nek5000-users-request at lists.mcs.anl.gov>
> >
> > You can reach the person managing the list at
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> >
> > When replying, please edit your Subject line so it is more specific
> > than "Re: Contents of Nek5000-users digest..."
> >
> >
> > Today's Topics:
> >
> > 1. Restarting with PNPN using PNPN-2 results
> > (nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>)
> > 2. Re: Restarting with PNPN using PNPN-2 results
> > (nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>)
> > 3. Re: Restarting with PNPN using PNPN-2 results
> > (nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>)
> > 4. Re: lambda2 in turbChannel (nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>)
> > 5. g2gi() no geometry found (nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>)
> > 6. Re: g2gi() no geometry found (nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>)
> >
> >
> >
> ----------------------------------------------------------------------
> >
> > Message: 1
> > Date: Mon, 13 Jun 2016 13:09:05 -0600
> > From: nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > To: nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > Subject: [Nek5000-users] Restarting with PNPN using PNPN-2 results
> > Message-ID:
> >
> > <mailman.23731.1465844987.24727.nek5000-users at lists.mcs.anl.gov
> > <mailto:
> mailman.23731.1465844987.24727.nek5000-users at lists.mcs.anl.gov>>
> > Content-Type: text/plain; charset="utf-8"
> >
> > Hello neks,
> >
> > I have a DNS simulation that I was running as PNPN-2 and I would
> like to
> > run it as PNPN without starting back at the initial conditions.
> > I am curious if anyone has experience running a PNPN case with
> initial
> > conditions from a PNPN-2 simulation? I have tried this and the
> > simulation
> > runs okay, except the pressure term never seems to converge when
> running
> > the PNPN simulation. This dramatically increases runtime and makes
> the
> > results questionable. It seems to me that restarting with PNPN-2
> > results
> > should be doable, and that it should only take a few iterations for
> the
> > pressure term to start converging. However, my simulation is still
> not
> > converging after 100+ iterations, but it was converging fine when I
> was
> > running PNPN-2.
> >
> > Any suggestions for things I should look for that might cause the
> > problem,
> > or potential fixes?
> >
> > Thanks
> > --
> > Phil Sakievich
> >
> > PhD Candidate - Mechanical Engineering
> > Arizona State University - Ira A. Fulton School for Engineering of
> > Matter
> > Transport and Energy
> > Tempe, Arizona
> > -------------- next part --------------
> > An HTML attachment was scrubbed...
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> http://lists.mcs.anl.gov/pipermail/nek5000-users/attachments/20160613/790d807b/attachment-0001.html
> >
> >
> > ------------------------------
> >
> > Message: 2
> > Date: Mon, 13 Jun 2016 19:15:32 +0000
> > From: nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > To: "nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>"
> > <nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>>
> > Subject: Re: [Nek5000-users] Restarting with PNPN using PNPN-2
> results
> > Message-ID:
> >
> > <mailman.23735.1465845499.24727.nek5000-users at lists.mcs.anl.gov
> > <mailto:
> mailman.23735.1465845499.24727.nek5000-users at lists.mcs.anl.gov>>
> > Content-Type: text/plain; charset="iso-8859-1"
> >
> > Hi Phil,
> >
> > The regularity of the pressure field is much larger for Pn-Pn as
> > compared to Pn-Pn-2 so it should take some time to readjust to the
> > larger resolution.
> >
> > Aleks
> > ________________________________
> > From: nek5000-users-bounces at lists.mcs.anl.gov
> > <mailto:nek5000-users-bounces at lists.mcs.anl.gov>
> > [nek5000-users-bounces at lists.mcs.anl.gov
> > <mailto:nek5000-users-bounces at lists.mcs.anl.gov>] on behalf of
> > nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > [nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>]
> > Sent: Monday, June 13, 2016 2:09 PM
> > To: nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > Subject: [Nek5000-users] Restarting with PNPN using PNPN-2 results
> >
> > Hello neks,
> >
> > I have a DNS simulation that I was running as PNPN-2 and I would
> > like to run it as PNPN without starting back at the initial
> conditions.
> > I am curious if anyone has experience running a PNPN case with
> > initial conditions from a PNPN-2 simulation? I have tried this and
> > the simulation runs okay, except the pressure term never seems to
> > converge when running the PNPN simulation. This dramatically
> > increases runtime and makes the results questionable. It seems to
> > me that restarting with PNPN-2 results should be doable, and that it
> > should only take a few iterations for the pressure term to start
> > converging. However, my simulation is still not converging after
> > 100+ iterations, but it was converging fine when I was running
> PNPN-2.
> >
> > Any suggestions for things I should look for that might cause the
> > problem, or potential fixes?
> >
> > Thanks
> > --
> > Phil Sakievich
> >
> > PhD Candidate - Mechanical Engineering
> > Arizona State University - Ira A. Fulton School for Engineering of
> > Matter Transport and Energy
> > Tempe, Arizona
> > -------------- next part --------------
> > An HTML attachment was scrubbed...
> > URL:
> > <
> http://lists.mcs.anl.gov/pipermail/nek5000-users/attachments/20160613/09bbb78b/attachment-0001.html
> >
> >
> > ------------------------------
> >
> > Message: 3
> > Date: Mon, 13 Jun 2016 21:31:08 +0200
> > From: nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > To: nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > Subject: Re: [Nek5000-users] Restarting with PNPN using PNPN-2
> results
> > Message-ID:
> >
> > <mailman.23743.1465847039.24727.nek5000-users at lists.mcs.anl.gov
> > <mailto:
> mailman.23743.1465847039.24727.nek5000-users at lists.mcs.anl.gov>>
> > Content-Type: text/plain; charset=windows-1252; format=flowed
> >
> > Hi,
> >
> > In principle, you can do a Navier-Stokes restart without pressure
> field.
> > For PnPn-2 you can for instance do one step with Uzawa (nested
> > iterations) to have a good pressure. So usually, when we do a
> restart of
> > a solution wi
> > thout pressure (e.g. when doing Arnoldi or Newton) then one Uzawa
> step
> > fixes everything. I am not too familiar with PnPn, but I guess that
> > there is a flavour that is not dependent on a previous pressure
> > solution. Perhaps a PnPn-expert has some opinion on a Uzawa-like
> method?
> >
> > Best regards,
> > Philipp
> >
> > On 2016-06-13 21:15, nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov> wrote:
> > > Hi Phil,
> > >
> > > The regularity of the pressure field is much larger for Pn-Pn as
> > > compared to Pn-Pn-2 so it should take some time to readjust to the
> > > larger resolution.
> > >
> > > Aleks
> > >
> >
> ------------------------------------------------------------------------
> > > *From:* nek5000-users-bounces at lists.mcs.anl.gov
> > <mailto:nek5000-users-bounces at lists.mcs.anl.gov>
> > > [nek5000-users-bounces at lists.mcs.anl.gov
> > <mailto:nek5000-users-bounces at lists.mcs.anl.gov>] on behalf of
> > > nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > [nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>]
> > > *Sent:* Monday, June 13, 2016 2:09 PM
> > > *To:* nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > > *Subject:* [Nek5000-users] Restarting with PNPN using PNPN-2
> results
> > >
> > > Hello neks,
> > >
> > > I have a DNS simulation that I was running as PNPN-2 and I would
> > like to
> > > run it as PNPN without starting back at the initial conditions.
> > > I am curious if anyone has experience running a PNPN case with
> initial
> > > conditions from a PNPN-2 simulation? I have tried this and the
> > > simulation runs okay, except the pressure term never seems to
> converge
> > > when running the PNPN simulation. This dramatically increases
> runtime
> > > and makes the results questionable. It seems to me that
> > restarting with
> > > PNPN-2 results should be doable, and that it should only take a few
> > > iterations for the pressure term to start converging. However, my
> > > simulation is still not converging after 100+ iterations, but it
> was
> > > converging fine when I was running PNPN-2.
> > >
> > > Any suggestions for things I should look for that might cause the
> > > problem, or potential fixes?
> > >
> > > Thanks
> > > --
> > > Phil Sakievich
> > >
> > > PhD Candidate - Mechanical Engineering
> > > Arizona State University - Ira A. Fulton School for Engineering of
> > > Matter Transport and Energy
> > > Tempe, Arizona
> > >
> > >
> > > _______________________________________________
> > > Nek5000-users mailing list
> > > Nek5000-users at lists.mcs.anl.gov
> > <mailto:Nek5000-users at lists.mcs.anl.gov>
> > > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
> > >
> >
> >
> > ------------------------------
> >
> > Message: 4
> > Date: Mon, 13 Jun 2016 16:11:14 -0700
> > From: nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > To: nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > Subject: Re: [Nek5000-users] lambda2 in turbChannel
> > Message-ID:
> >
> > <mailman.23757.1465860244.24727.nek5000-users at lists.mcs.anl.gov
> > <mailto:
> mailman.23757.1465860244.24727.nek5000-users at lists.mcs.anl.gov>>
> > Content-Type: text/plain; charset="utf-8"
> >
> > Hi Wei,
> >
> > I do not think so. But you can definitely, modify the lambda2()
> > routine to
> > generate the Q criterion. It is quite straightforward.
> > -------------- next part --------------
> > An HTML attachment was scrubbed...
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> http://lists.mcs.anl.gov/pipermail/nek5000-users/attachments/20160613/40eedaf9/attachment-0001.html
> >
> >
> > ------------------------------
> >
> > Message: 5
> > Date: Tue, 14 Jun 2016 11:21:16 +0200
> > From: nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > To: nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > Subject: [Nek5000-users] g2gi() no geometry found
> > Message-ID:
> >
> > <mailman.23773.1465903728.24727.nek5000-users at lists.mcs.anl.gov
> > <mailto:
> mailman.23773.1465903728.24727.nek5000-users at lists.mcs.anl.gov>>
> > Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes";
> > format="flowed"
> >
> > Hello Neks,
> >
> > I am trying to use the g2gi subroutine, but keep getting the error
> > massage ABORT: No geometry found in:
> >
> > call userchk
> > grid-to-grid interpolation
> > 140 8 8 8 2.0010000E+03 4002 U P
> 4
> > NELT,NX,N ?a?@
> >
> > NONSTD HDR, parse_hdr, abort.
> > ABORT: No geometry found in newgeom.fld
> >
> > call exitt: dying ...
> >
> > Anybody familiar with this error? Do I give him the wrong files? I
> > assumed Nek wants a .fld. Any help or working case as an example
> would
> > be highly appreciated.
> >
> > Br
> > Michael
> > e1429308 at student.tuwien.ac.at <mailto:e1429308 at student.tuwien.ac.at>
> >
> >
> >
> >
> >
> >
> > ------------------------------
> >
> > Message: 6
> > Date: Tue, 14 Jun 2016 11:40:05 +0000
> > From: nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > To: "nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>"
> > <nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>>
> > Subject: Re: [Nek5000-users] g2gi() no geometry found
> > Message-ID:
> >
> > <mailman.23774.1465904407.24727.nek5000-users at lists.mcs.anl.gov
> > <mailto:
> mailman.23774.1465904407.24727.nek5000-users at lists.mcs.anl.gov>>
> > Content-Type: text/plain; charset="us-ascii"
> >
> >
> > Hi Michael,
> >
> > You need to compile with the ifmpiio flag set in makenek:
> >
> >
> > # (set PPLIST=? to get a list of available symbols)
> > PPLIST="MPIIO"
> >
> > All files should be .f00000 files, which is the current default.
> > (Make certain that your
> > current .usr file does not reset param(66) to 4.) [ You can
> > convert a .fld file to a .f0000
> > file by running a 0 step, 0 FINTIME job and setting p66=6, p67=4 in
> > the .usr file, say, in
> > subroutine usrdat(). ]
> >
> > When running g2gi, make certain that the new file has the geometry
> > in it. The old file does not need the
> > geometry, only the data to be interpolated.
> >
> > hth
> >
> > Paul
> >
> >
> > ________________________________________
> > From: nek5000-users-bounces at lists.mcs.anl.gov
> > <mailto:nek5000-users-bounces at lists.mcs.anl.gov>
> > [nek5000-users-bounces at lists.mcs.anl.gov
> > <mailto:nek5000-users-bounces at lists.mcs.anl.gov>] on behalf of
> > nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > [nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>]
> > Sent: Tuesday, June 14, 2016 4:21 AM
> > To: nek5000-users at lists.mcs.anl.gov
> > <mailto:nek5000-users at lists.mcs.anl.gov>
> > Subject: [Nek5000-users] g2gi() no geometry found
> >
> > Hello Neks,
> >
> > I am trying to use the g2gi subroutine, but keep getting the error
> > massage ABORT: No geometry found in:
> >
> > call userchk
> > grid-to-grid interpolation
> > 140 8 8 8 2.0010000E+03 4002 U P
> 4
> > NELT,NX,N ?a?@
> >
> > NONSTD HDR, parse_hdr, abort.
> > ABORT: No geometry found in newgeom.fld
> >
> > call exitt: dying ...
> >
> > Anybody familiar with this error? Do I give him the wrong files? I
> > assumed Nek wants a .fld. Any help or working case as an example
> would
> > be highly appreciated.
> >
> > Br
> > Michael
> > e1429308 at student.tuwien.ac.at <mailto:e1429308 at student.tuwien.ac.at>
> >
> >
> >
> >
> > _______________________________________________
> > Nek5000-users mailing list
> > Nek5000-users at lists.mcs.anl.gov <mailto:
> Nek5000-users at lists.mcs.anl.gov>
> > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
> >
> >
> > ------------------------------
> >
> > _______________________________________________
> > Nek5000-users mailing list
> > Nek5000-users at lists.mcs.anl.gov <mailto:
> Nek5000-users at lists.mcs.anl.gov>
> > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
> >
> >
> > End of Nek5000-users Digest, Vol 88, Issue 13
> > *********************************************
> >
> >
> >
> >
> > --
> > Phil Sakievich
> >
> > PhD Candidate - Mechanical Engineering
> > Arizona State University - Ira A. Fulton School for Engineering of
> > Matter Transport and Energy
> > Tempe, Arizona
> >
> >
> > _______________________________________________
> > Nek5000-users mailing list
> > Nek5000-users at lists.mcs.anl.gov
> > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
> >
>
>
> ------------------------------
>
> _______________________________________________
> Nek5000-users mailing list
> Nek5000-users at lists.mcs.anl.gov
> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>
>
> End of Nek5000-users Digest, Vol 88, Issue 15
> *********************************************
>
--
Phil Sakievich
PhD Candidate - Mechanical Engineering
Arizona State University - Ira A. Fulton School for Engineering of Matter
Transport and Energy
Tempe, Arizona
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